Thumb tacks.
(Insanity #417)

I compulsively steal things, but one of them is thumb tacks. Anytime I see one on campus that isn't used, I pocket it. I've poked myself several times putting my hands in my jacket, for there are usually two or three in there all winter.

I kinda do the poking thing too... Although I dont steal anything, I will press the point of the graphite into my finger to avoid situations in which I may oddly laugh in an situation that is un humourous, etc...